For example, Publication Gazette of Unexamined Japanese patent application Sho 61-10457 describes a conventional solid article conveyor where solid articles such as the tablets, capsules and the like are regularly arranged in pockets which are formed on an outer surface of a drum and the solid articles are conveyed to a process such as printing, PTP packaging and the like.
In the conventional solid article conveyor, numerous pockets are formed on an outer surface of a feeding drum. Each pocket generally has a depth shallower than the largest dimension (diameter) of a solid article in a radial direction perpendicular to a rotation axis of the drum, and has a sectional area wider than the largest sectional area of the solid article in a direction parallel to the rotation axis of the drum. Thus, the solid article is contained in the pocket in a manner so that a section where the solid article has the largest sectional area becomes parallel to the rotation axis of the drum, in a normal operation (not shown in the figure).
A troublesome case of conveyance of solid articles in the conventional solid article conveyor is shown in FIG. 4. As shown in FIG. 4, the pockets 2a to 2d formed on the drum 1 have a depth shallower than the largest dimension of the solid articles 100a to 100d in the radial direction of the drum 1, and have a sectional area wider than the largest sectional area of the solid articles 100a to 100d in the rotation axis of the drum 1. Thus, it is possible that the solid articles 100a to 100d are not normally contained with the pockets 2a to 2d. For example, in the pocket 2a, a plurality of (two) solid articles 100a are contained in one pocket, and the solid articles 100a stand up. In the pocket 2b, the solid article 100b rests on the edge of the pocket 2b. In the pocket 2c, the solid article 100c is not placed at the normal position in the pocket 2c. In the pocket 2d, the solid article 100d is standing, similar to those in the pocket 2a. Namely, the solid articles 100a to 100d protrude from the pockets 2a to 2d.
If the solid articles 100a to 100d, which are abnormally contained in the pockets 2a to 2d, are conveyed to a process such as printing, PTP packaging and the like, the protruding solid articles 100a to 100d will jam between the drum 1 and a guide and the like (not shown in the figure). Thus, the conveyor will not be able to move. Otherwise, the jammed solid articles will be crushed, and the circumferences of the conveyor will be soiled. For preventing such troubles shown in FIG. 4, a brush roller 3 is generally provided above and in the vicinity of the drum 1 for removing or repelling the solid articles 100a to 100d which are abnormally contained in the pockets 2a to 2d.
When the solid articles 100a to 100d in the pockets 2a to 2d are removed, the jamming of the solid articles between the drum and the guide can be prevented. The pockets 2a to 2d, however, are emptied by removing the solid articles 100a to 100d. Thus, the empty pockets derive the following new troubles.
In a solid article printer, the quantity of an ink spread on a transfer roller should be adjusted to just the quantity necessary to print a pattern on a surface of one solid article. If a pocket of the conveyor is not filled by the solid article, the ink pattern on the transfer roller may not be transferred to any solid article and will remain on the transfer roller. When a new ink pattern is spread over the old ink pattern on the transfer roller in the next printing operation, the quantity of the ink pattern on the transfer roller will be surplus. Thus, the surplus ink will be the cause of printing errors. For example, the printed pattern such as a letter, a mark and the like will be blotted or the lines of the pattern will be widened.
On the other hand, in a PTP packer, PTP packages having numerous pockets are supplied in synchronism with the conveyance of the solid article. If a pocket of the conveyor is not filled by the solid article, the pocket of the PTP package corresponding to the empty pocket of the conveyor will be empty. As a result, an inferior package in which at least one pocket is left empty may occur.